This invention relates to a system for constructing an image of a diseased portion of a patient as a three-dimensional image and determining an operation route on the basis of the three-dimensional image, in particular, an operation route searching apparatus for supporting the determination of an invasion route through which an instrument such as a puncturing needle is introduced into the body of the patient during an operation, and the searching method.
In general, it is very important problem for a surgical operation to specify a diseased portion of a patient, and to determine from what position outside the body and at what angle an instrument such as a puncturing needle is introduced into the body of the patient in order to approach the diseased portion.
For example, in the stereotaxy (the guided stereotaxy) which should be low-invasively performed, an operation instrument having a frame capable of precisely moving its own X, Y, and Z axes fixed to a head of the patient so as to surround the head. By adjusting scales on coordinates axes of a puncture guide instrument fixed to the frame of this operation instrument, the three-dimensional operation route in the three-dimensional space is determined, through which the instrument is introduced into the brain.
Prior to the introduction of the instrument into the brain of the patient, an operator specifies the position of the diseased portion in the brain on the basis of various data obtained in advance (with use of MRI, X-ray CT, and the like), and determines the most suitable introduction route (i.e., an operation route) through which an instrument such as a puncturing needle is introduced into the skull and guided to the diseased portion, and then performs the operation.
Most of examination data used as criteria of the determination of the route are, however, obtained from two-dimensional tomography films. The operator must grasp an outline of the diseased portion of the patient three-dimensionally and spatially from these numerous tomography films, imagine the three-dimensional image of the diseased portion, and determine an operation route and the actual operation plan from his/her own experience.
The determination of the operation route is not such a simple process as the mere determining of a linear invasion route. The operator must determine in the process whether or not there exists in the operation route any brain functional region, which administrates the functions of supporting the life, motions, or functions of the body, or any physiologically important region. The determination process is thus a very complicated work requiring a long period of time and so-experienced skill.
In order to support the operation route determination, a system for inputting the image data into a computer during the examination, thereby constructing the image data as a two-dimensional or three-dimensional computer graphics image has been proposed.
For example, the Published KOKAI Patent Application No. 3-162849 proposes a system for supporting the operation route determination. According to this system, a plurality of two-dimensional images obtained by a CT scanner are stacked to obtain a perspective image. Then, a diseased portion and an intended invasion position on the surface of a head, from which an instrument is introduced into the skull, are specified in the display of a monitor. Subsequently, the positional information of the operation route is input in the system. On the basis of the positional information, the operator calculates the puncturing needle invasion route spatially and displays it, thereby can determine whether or not the invasion route is the most suitable one.
According to this system, however, when any brain functional region or physiologically important region exists in the operation route calculated from the specified invasion position, the above-mentioned process must be repeated: specifying of the diseased portion and the intended invasion position; and calculating of the invasion route. The specifying process must be repeated till the specified operation route is found not to include any brain functional region or physiologically important region, and thus a very long period of time is required for the specifying process.
Further, in some actual operation, the operation route must inevitably pass through some of the brain functional regions or physiologically important regions depending on the position of the diseased portion in the head, wherever on the head surface the operation instrument invades from. The operator must thus determine which operation route attains the minimum invasion in every determination process of the operation route. The determination process therefore takes a very long period of time.
The object of the present invention is to provide an operation route searching apparatus for searching an operation route by obtaining under various conditions a plurality of candidates of an invasion route through which an instrument such as a puncturing needle is introduced from the outside of the body to the diseased portion so as to three-dimensionally avoid regions the invasion into which may affect the body function of a patient and physiologically important regions of a patient, in order to show an operator a guideline for a strategy of a low-invasive and the most suitable operation, and a searching method thereof.
In order to attain the above-mentioned object, the present invention provides an operation route searching apparatus comprising: an input section for inputting a plurality of images obtained by tomography of a body including a diseased portion; a specifying section for allowing an operator to specify the diseased portion included in the images; a conversion section for converting the specified diseased portion into a three-dimensional structure; a geometrical center calculation section for calculating a geometrical center point of the three-dimensional structure as a center of the diseased portion; and a linear line calculation section for calculating a linear line as an operation route directed to the geometrical center point from outside of the body.
The present invention further provides an operation route searching method comprising: inputting a plurality of images obtained by tomography of a body including a diseased portion; enabling an operator to specify the diseased portion included in t he images; converting the specified diseased portion for each image into a three-dimensional structure; calculating a geometrical center point of the three-dimensional structure as a center of said diseased portion; and calculating a linear line as an operation route directed to the geometrical center point from outside of the body.
According to the operation route searching apparatus having the above-mentioned constitution and the searching method, a plurality of obtained two-dimensional image data are input into a computer or the like to be hierarchically displayed on a display. Among them, the diseased portion data is converted into a three-dimensionally constructed image and displayed. The geometrical center of the three-dimensionally constructed image is obtained by a calculation to obtain a plurality of linear lines directing from the geometrical center of the three-dimensional construction to the outside of the body or the shortest one of the linear lines. The lines or the shortest line is then displayed to be overlapped on the three-dimensional construction in order to provide an operator with a guideline for a low-invasive operation strategy.
Additional objects and advantages of the invention will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. The objects and advantages of the invention may be realized and obtained by means of the instrumentalities and combinations particularly pointed out hereinafter.